Virtual Lab Environment Manager

gestiona-pc1.py is a Python script designed to automate the creation, configuration, and management of a virtualized network environment. Its main purpose is to deploy a Load Balancer (LB) scenario using QEMU/KVM (libvirt), configurable web servers, and virtual bridges, simplifying the setup of complex network labs for testing and educational purposes.

💡 Main Objective

The primary goal is to provide a single command-line interface to manage a complete load balancing scenario, including:

• Automated VM Provisioning: Create disk images (.qcow2) and definition files (.xml) from templates.
• Network Setup: Configure Linux bridges (LAN1, LAN2) and host routing to interconnect the scenario.
• Service Configuration: Automatically configure networking (IPs, gateways, hostnames) and critical services like HAProxy.
• Lifecycle Management: Handle VM start, stop, reboot, and complete destruction of the virtual lab.

The resulting architecture consists of a client LAN (LAN1) separated from a server farm LAN (LAN2) by the load balancer.

🛠️ Technology and Dependencies

Core Technologies

• Virtualization Backend: QEMU/KVM managed via libvirt (virsh).
• Disk Image Management: qemu-img to create copy-on-write images from a base.
• VM Configuration: libguestfs-tools (virt-copy-in, virt-edit) for VM customization before first boot.
• Network Abstraction: Linux Bridges (brctl) to define virtual LANs.
• Load Balancing Service: HAProxy configured in Round Robin mode.

Python Requirements

• sys, os, json, subprocess
• lxml for programmatic manipulation of libvirt XML files
• logging for structured debug and informational output

🚀 Usage Guide

python3 gestiona-pc1.py <command> [sub-parameters]

Key Commands

Command	Description	Example
create	Builds the entire scenario. Configurable with the number of servers (1-5) and debug flag.	python3 gestiona-pc1.py create 3 debug
start	Boots the VMs and opens an xterm console for interaction.	python3 gestiona-pc1.py start lb
stop	Shuts down the specified VM(s) using virsh shutdown.	python3 gestiona-pc1.py stop s1
destroy	CLEANUP: Stops all VMs, undefines them, deletes all generated files (.qcow2, .xml, etc.), and removes the bridges.	python3 gestiona-pc1.py destroy
monitor	Provides real-time status or diagnostics of a VM.	python3 gestiona-pc1.py monitor lb cpu
reboot	Restarts the specified VM(s).	python3 gestiona-pc1.py reboot
--help	Displays the full usage guide.	python3 gestiona-pc1.py --help

Monitor Sub-Parameters

The monitor command requires a VM name (c1, lb, or sX) and a function:

Function	Description
ping	Performs a 5-packet connectivity test from the host to the VM.
info	Displays detailed VM information (virsh dominfo) in a live watch window.
estado	Shows the current power state of the VM (virsh domstate) in a live watch window.
cpu	Displays VM CPU statistics (virsh cpu-stats) in a live watch window.

📁 Artifacts Generated

The following files and configurations are created by the create command and removed by the destroy command:

• gestiona-pc1.json – Stores scenario configuration (number of servers, debug flag).
• <VM>.qcow2 – VM disk images (c1.qcow2, lb.qcow2, sX.qcow2).
• <VM>.xml – libvirt VM definition files.
• LAN1, LAN2 – Virtual Linux bridges.
• Temporary configuration files used for VM customization:
  • hosts
  • hostname
  • interfaces
  • haproxy.cfg
  • rc.local
  • index.html